This invention relates to apparatus and method for verifying the aim of certain accessory equipment on a land vehicle, more especially apparatus and method for verifying the beam axis of a front-looking radar antenna on a land motor vehicle, such as a heavy truck.
The continuing expansion of the application of electronic devices and systems to motor vehicles has enabled vehicles to be equipped with radar systems that can look in the forward direction of vehicle travel to disclose objects that may present a hazard to the vehicle. A Doppler radar transceiver enables the detection of objects that a driver of the vehicle may be unable to visually perceive.
An important aspect of equipping a vehicle with such a radar system involves properly aiming a front-looking antenna. The antenna must be aimed with a sufficient degree of accuracy to assure a correct final alignment of the antenna beam axis for detecting objects in the path of forward vehicle travel. In this regard, proper angles of the antenna beam axis in both elevation and azimuth are particularly important.
New motor vehicles are typically assembled on assembly lines where it is important for assembly operations to be conducted with dispatch, efficiency, and accuracy. While a level indicating instrument, such as a digital level, could be quickly placed by hand on an antenna to measure its angle of elevation after the antenna has been installed as a vehicle is being assembled on an assembly line, manual placement of such an instrument on an antenna may not occur with sufficient accuracy and/or repeatability to consistently assure a final mounting that provides proper antenna alignment, particularly in elevation. Moreover, a particular shape of an antenna may not be conducive to use of such an instrument, which often requires placement on a flat surface.
Consequently, a preferred practice is to complete the installation of the antenna at an off-line operation where the antenna can be finally secured in the proper alignment. Efficiency, dispatch, and accuracy remain important in an off-line operation.
The present invention relates to apparatus and method for accomplishing proper antenna alignment with efficiency, dispatch, and accuracy.
The apparatus comprises fixtures that are secured to the antenna and vehicle respectively by attending personnel. Once the fixtures have been so secured, the attending personnel perform additional procedures for verifying proper antenna alignment and securing the antenna in proper alignment.
The inventive apparatus and method are concerned initially with measuring, and if necessary adjusting, the angle of elevation of the antenna beam axis, and then securing the antenna once the proper angle of elevation has been verified by measurement. The method for measuring angle of elevation comprises securing to the antenna a fixture that comprises an indicator for indicating angle of elevation. The fixture comprises a locator for fitting congruently to a perimeter rim of the antenna and a mechanism for releasably securing the locator to the antenna to correlate the locator to the angle of elevation of the antenna beam axis. An indicator mounted on the locator indicates the angle of elevation of the locator, and hence the angle of elevation of the antenna.
A further, but optional, aspect of the method assures that the beam axis of the antenna is properly positioned in azimuth to be parallel to the thrust angle of the vehicle. The fixture just described is modified to include a first optical laser for emitting a first laser beam in a direction that, as viewed normal to a horizontal surface on which the vehicle is disposed for travel, is parallel to the beam axis of the antenna. A second fixture comprises a second optical laser that emits a second laser beam aimed in a direction that, as viewed normal to the horizontal surface, is parallel to the direction of forward vehicle travel, or thrust angle of the vehicle. The second laser is aligned with the first laser such that their respective beams are contained in a common vertical plane. A target is placed on the horizontal surface in front of the vehicle such that the second laser beam shines on a vertical centerline of a defined zone on a vertical face of the target. The first laser is then turned on to shine its beam on the target. Proper alignment in azimuth is indicated by the first laser beam shining within the defined zone on the target face.
Accordingly, one general aspect of the present invention relates to a method for measuring the angle of elevation of the beam axis of a front-looking radar antenna on a land vehicle, as just described.
A further aspect relates to a method for verifying the alignment of the antenna beam axis in azimuth, as just described.
Another general aspect of the present invention relates to a method for measuring the angle of elevation at which a device mounted on a land vehicle radiates electromagnetic radiation along a beam axis that, as viewed normal to a horizontal surface on which the vehicle is disposed for travel, is parallel to a direction of travel of the vehicle along the surface.
The method comprises securing to the device a fixture that comprises at least an indicator for indicating angle of elevation. The fixture comprises a locator for fitting congruently to a perimeter rim of the device and a mechanism for releasably securing the locator to the device to correlate the locator to the angle of elevation of the beam axis. An indicator mounted on the locator indicates the angle of elevation of the locator, and hence the angle of elevation of the beam axis.
A further aspect relates to a method for verifying the alignment of the beam axis in azimuth using a modified first fixture and a second fixture, as described earlier.
Still another general aspect of the present invention relates to apparatus for measuring the angle of elevation at which a device mounted on a land vehicle radiates electromagnetic radiation along a beam axis that, as viewed normal to a horizontal surface on which the vehicle is disposed for travel, is parallel to a direction of travel of the vehicle along the surface.
The apparatus comprises a fixture that comprises a locator for fitting congruently to a perimeter rim of the device and a mechanism for releasably securing the locator to the device to correlate the locator to the angle of elevation of the device, and an indicator mounted on the locator for indicating angle of elevation of the locator, and hence angle of elevation of the device.
The foregoing, along with further features and advantages of the invention, will be seen in the following disclosure of a presently preferred embodiment of the invention depicting the best mode contemplated at this time for carrying out the invention. This specification includes drawings, now briefly described as follows.